The origins of “Eight Days A Week” are when McCartney asked his driver if he’d been busy lately- to which he replied: “Busy! I’ve been working eight days a week.”
Both this song and “You Won't See Me" lifted the chord sequence from The Four Tops' “It's the Same Old Song.” McCartney later admitted, "we were the biggest nickers in town."
Lennon said of the track:
“We struggled to record it and struggled to make it into a song. But it was lousy anyway.”
One view of “Eight Days A Week” is that the whole was indeed greater than the sum of the parts as everyone nails their note, and the blend creates something extra in the sound. They produced that essence in so many of their songs but in this one they take it to a completely different level. McCartney’s Hofner bass defined the rolling, moving feel to the track.
The alternative view is that it was somewhat overrated - a bit simplistic and unbalanced: it doesn't even find time for an instrumental passage, preferring instead to repeat each verse twice. The components of the song don’t add up the way the actual performance does. Lacking any single distinctive feature, it relies completely on the novelty of the underlying harmonies for interest. It surprised many that without any single dramatic ear-catching sound gesture how it was so successful as a single release.
The song is a mixture of styles bordering on country but with spots of rock’n’ roll. It holds it place with its sheer verve and the embraching warmth of its sound. Throughout the recording, Ringo’s beat swerves between teasing and tantalizing and the, stopping short before suspending it in mid-air. It is hard to see any other drummer able to display such mastery over his self-control.
“Eight Days A Week” was the first pop song to begin with a fade-in.
Beatle scholar Alan Pollack explains:
“The harmony of the song is built out of a wonderfully teasing exploitation of the special effect called a "false (or "cross") relation". This harmonic idiom is used quite a bit throughout the Beatles' output. The final part of the outro is musically identical to the intro but the decision to neither repeat the fade-in, or even worse to change it into a truly symmetrical fade-out, is a good example of avoiding foolish consistency.”
The narrator loves a girl so much and he is telling her that she is always on his mind. He is thinking about her so much- almost the whole week and he is thinking about her so much as if there eight days a week.
The Beatles are saying that love isn't a job, it's a privledge, and this song expresses its power to stretch out beyond the physical limitations of seven days a week.